Since the W10 upgrade to v1511, I've been pestered with a giant "Upgrade" MS popup, even though I have a fully activated Product Key and W10 system. The file name even included the word popup! I tried several blocking extensions, e.g. Adblock Plus, which I always had enabled, NoScript, uBock, etc. but nothing worked. The constant was it always happened opening Ff after running CC. Our homepage is MSN. It never happened using edge. I then discovered that if Sandboxie's "Forced Programs" was disabled it didn't occur. Now here is where it really gets bizarre: I'm not even sure how I discovered it but...I launch Ff from a Sandboxie quick launch icon, however, again I don't even know why I tried the following but if I launch Ff from a Ff icon (or shortcut), even with Sandboxie enabled, no issue. You have no idea how this has been bugging me! Merry c Christmas!